Atrial Fibrillation (AF) is a cardiac arrhythmia that carries significant morbidity and mortality for greater than 2.2 million Americans. Recent studies demonstrate treatment of AF using catheter-based ablation. Ablating, or destroying the function of, tissue in different patterns in the left atrium (typically lines surrounding the pulmonary veins to block the propagation of AF triggering foci outward from the pulmonary veins) has been accepted as an effective treatment for AF. However, conventional ablation methods have many problems that have limited the efficacy of this treatment. In order to block electrical propagation, clinicians deliver energy to the tip of long thin tubes called catheters. The energy kills tissue at one point, then the catheter is to be moved to an adjacent point and energy is delivered again. This point-by-point process (conventional catheter ablation) is repeated until contiguous lines of ablated tissue are formed. As shown in FIG. 1, the posterior left atrium 100 includes pulmonary veins (LSPV, LIPV, RSPV, and RIPV). Each circular spot is a therapy delivery point of ablation 102. The pattern of ablation, as shown in FIG. 1, is one of many that clinicians use to treat AF. This conventional technique is time-consuming and requires significant skill because catheters are hard to manipulate and maneuver accurately inside a beating heart. It is difficult to: 1) place adjacent lesions and 2) maintain tissue contact (a necessity in creating a quality lesion). With significant gaps between lesions and poor tissue contact, contiguous lines of ablated tissue—and therefore effective conduction block—cannot be achieved.
Thus, there is a need in the medical device field to create a new and useful system for delivering therapy. This invention provides such improved a new and useful system.